Disclosed herein are resins suitable for use in toner compositions used in imaging applications. More specifically, disclosed herein are rosin-derived resins and toners containing these resins.
The formation and development of images on the surface of photoconductive materials by electrostatic means is well known. The basic electrophotographic imaging process, as taught by C. F. Carlson in U.S. Pat. No. 2,297,691, entails placing a uniform electrostatic charge on a photoconductive insulating layer known as a photoconductor or photoreceptor, exposing the photoreceptor to a light and shadow image to dissipate the charge on the areas of the photoreceptor exposed to the light, and developing the resulting electrostatic latent image by depositing on the image a finely divided electroscopic material known as toner. Toner typically comprises a resin and a colorant. The toner will normally be attracted to those areas of the photoreceptor which retain a charge, thereby forming a toner image corresponding to the electrostatic latent image. This developed image may then be transferred to a substrate such as paper. The transferred image may subsequently be permanently affixed to the substrate by heat, pressure, a combination of heat and pressure, or other suitable fixing means such as solvent or overcoating treatment.
Numerous processes are within the purview of those skilled in the art for the preparation of toners. Emulsion aggregation (EA) is one such method. Emulsion aggregation toners can be used in forming print and/or xerographic images. Emulsion aggregation techniques can entail the formation of an emulsion latex of the resin particles by heating the resin, using emulsion polymerization, as disclosed in, for example, U.S. Pat. No. 5,853,943, the disclosure of which is totally incorporated herein by reference. Other examples of emulsion/aggregation/coalescing processes for the preparation of toners are illustrated in, for example, U.S. Pat. Nos. 5,278,020, 5,290,654, 5,302,486, 5,308,734, 5,344,738, 5,346,797, 5,348,832, 5,364,729, 5,366,841, 5,370,963, 5,403,693, 5,405,728, 5,418,108, 5,496,676, 5,501,935, 5,527,658, 5,585,215, 5,650,255, 5,650,256, 5,723,253, 5,744,520, 5,747,215, 5,763,133, 5,766,818, 5,804,349, 5,827,633, 5,840,462, 5,853,944, 5,863,698, 5,869,215, 5,902,710; 5,910,387; 5,916,725; 5,919,595; 5,925,488, 5,977,210, 5,994,020, 6,576,389, 6,617,092, 6,627,373, 6,638,677, 6,656,657, 6,656,658, 6,664,017, 6,673,505, 6,730,450, 6,743,559, 6,756,176, 6,780,500, 6,830,860, and 7,029,817, and U.S. Patent Publication No. 2008/0107989, the disclosures of which are totally incorporated herein by reference.
Polyester EA ultra low melt (ULM) toners have been prepared utilizing amorphous and crystalline polyester resins as disclosed in, for example, U.S. Pat. No. 7,547,499, the disclosure of which is totally incorporated herein by reference.
Two exemplary emulsion aggregation toners include acrylate based toners, such as those based on styrene acrylate toner particles as illustrated in, for example, U.S. Pat. No. 6,120,967, and polyester toner particles, as disclosed in, for example, U.S. Pat. Nos. 5,916,725 and 7,785,763 and U.S. Patent Publication 2008/0107989, the disclosures of each of which are totally incorporated herein by reference.
Energy and environmental policies, increasing and volatile oil prices, and public/political awareness of the rapid depletion of global fossil reserves has created a need to find sustainable monomers derived from biomaterials. By using bio-renewable feedstock, manufacturers can reduce their carbon footprint and move to a zero-carbon or even a carbon-neutral footprint. Bio-based polymers are also very attractive in terms of specific energy and emission savings. Using bio-based feedstock can decrease the amount of plastic targeted for landfills, help provide new sources of income for domestic agriculture, and reduce the economic risks and uncertainty associated with reliance on petroleum imported from unstable regions.
While known compositions and processes are suitable for their intended purposes, a need remains for improved resins and toner compositions. In addition, a need remains for resins and toners derived from sources other than petroleum and/or from renewable resources. Further, a need remains for resins and toners derived from sources other than bisphenol-A. Additionally, a need remains for toners having concurrent good fusing performance and good electrical performance. There is also a need for toners derived from relatively inexpensive sources. In addition, there is a need for emulsion aggregation toners having the aforementioned advantages. Further, there is a need for emulsion aggregation toners derived either from petroleum-based sources or from renewable resources that do not contain bisphenol-A and that can be obtained in high yield, have small particle size, have controlled particle morphology or shape, have a narrow particle size GSD, and have a core-shell structure.